Neons and Sync Gaps

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Neons and Sync Gaps
From: Tesla List <tesla-at-stic-dot-net>
Date: Wed, 24 Sep 1997 23:52:11 -0500
Approved: tesla-at-stic-dot-net

From: 	Jason Judd[SMTP:Jason.Judd-at-anu.edu.au]
Sent: 	Wednesday, September 24, 1997 10:49 PM
To: 	Tesla List
Subject: 	Re: Neons and Sync Gaps

Hi Malcolm and all,

I am starting to think that the voltage at which a static gap fires at has
almost nothing to do with the gap distance. Last night I installed another
15 Kv 30Ma neon in my setup giving me 15Kv at 90Ma. With a smaller gap I
was able to get 3' sparks like before, but now they are really powerful
white hot arcs as well. When I removed one neon the sparks were only 2 foot
and thin again. All the neons have been tested together and individually
and are fine.

I would assume that the capacitor voltage before breakdown is the same and
hence the stored energey would be the same. So why am I getting a 33%
increase in spark length and sparks that are at least twice the diameter. I
would estimate that there is between 50 and 100% more power in the arcs.
Even with 2 neons and the gaps set much wider I don't get sparks any where
near this quality.

At no time under any setting has my gap failed to fire.Primary cap is 14.3
nF. I have not measured the input current , but that is next on my list. 

>     BTW, the unpotting is a horribly messy business. However, I'm 
> indebted to Richard Quick for the information he provided which gave 
> me the inspiration I needed.
>     Lastly, the gap distances and known o/c peak output voltage of 
> the transformer suggests the 35kV/inch rule is a very useful guide 
> for these sorts of distances. 
> 
> I am going to place a caveat on this. I regard the above guide as 
> true for sharpened wire ends. However, nice rounded electrodes should 
> have this figure doubled IMO. I think based on observation (plus 
> information from Glasoe and HPE) that 70kV/inch is far more realistic
> for a typical gap electrode. In other words, if you static gap is set 
> at 1/2", you are probably firing at 30kV+ so watch those transformers.

I think I will head your advice on this and am glad that I have not killed
any neons yet :-)
It would be interesting to watch the tank and gap voltages on a scope and
see just what is happening. Has anyone done this or have a good way of
doing it ?

> I have Jason in mind while saying this. According to this then, my 
> setup was firing at around 17kV which was the o/c peak transfromer 
> voltage. Sorry for equivocating once again :(
> 
> Malcolm
> 
> 

Cheers,

Jason